Lone Star, with 8 million made, there's bound to be a few lemons. Your experience is atypical.
Re the lawsuit....
Early 870 barrels were well made and of good steel. It was slightly softer than the nickel steel used in Model 12 barrels, but it would take extensive Rockwell testing to know the difference.
Some early 870 barrels blew out and the folks that owned them sued Remington. Even though the NRA tested and blew up numerous barrels in their labs and found the damage pattern consistent with obstruction in the barrels, their testimony wasn't allowed, and idiots on the bench and in the jury box awarded lots of money to not only the idiot plaintiffs but all 870 owners. I never applied for it, and regard the whole mess as a classic example of rule by mob.
BTW, the NRA ran one barrel with triple overloads of about 40,000 PSI and it held together. They then took the same barrel outside in the snow and plugged the muzzle with one inch of new, unpacked snow. On firing a low pressure round, the barrel duplicated those sued over. Kablooey...
Newer barrels were made with thicker walls, design by lawyers and not gunsmiths. The newer Light Contour barrels are more like those of old, with a slightly stronger alloy.
That's not limited to Remington or even just 870s. Darn near all US made barrels now are made of better steels than those of yesteryear.